121 



Another cause of disappearance of species, especially butter- 

 flies, and also the tendency of certain insects to become much 

 darker than the original type, is, I think, due to the changed 

 meteorological conditions, but this is a matter that can be 

 better worked out by meteorologists, it being only an assump- 

 tion on my part that the years seem to be getting more of an 

 equable temperature, instead of what our elders talk of as the 

 old-fashioned cold winters and hot summers. The alteration of 

 the weather in the way mentioned, i.e. having cold and warm 

 snaps of weather during the winter months, would, in the case 

 of the warmer spells of weather, tend to bring insects out in 

 the earlier stages before their time, and then a cold snap comes 

 and there is an end to the venturesome species, perhaps a total 

 eclipse for the district affected 



Good ground for working is by railway embankments, 

 where it is often more sheltered, and the vegetation is more in a 

 wild state, not being troubled by agriculturists ; but these also 

 have their drawbacks, such as the sparks from a passing engine 

 occasionally setting the herbage on fire, and, of course, destroying 

 ■everything with it. And then there is also the difficulty of 

 •working railway embankments without being liable to the 

 penalty of the law. 



Before connnencing the list of species, I should like to ask 

 members and others who are working up the Lepidoptera of 

 the district for their assistance in the preparation of a list of 

 the species that occur in Cleveland, and it would be much more 

 useful if they would at the same time let rue have the earliest 

 and latest dates on which the various species occur, together 

 with any notes as to the variation, habits, local distribution, 

 etc. 



I should also be glad to receive from non-Lepidopterist 

 members airy insects, larvae, etc., for the purpose of naming, and 

 all assistance would be very acceptable, the work rrot being one 

 that can be accnurpli.-hed by one person. 



I have included a few species in [ ] that have not 



been recorded for the Cleveland district, but are likely to occur, 

 having occurred iir adjacent districts. 



Diurni. CoHas edusa. — This in.sect is, of course, as far as 

 this district is concerned, migratory, and thus of only very 

 occasional appearance. 



Stokesley — Reported some years since. 



